127 research outputs found

    Improving the oral screening with optical fluorescence

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    A fluorescência óptica pode ser utilizada como um coadjuvante ao exame clínico bucal, uma vez que permite, por autofluorescência, a detecção de inúmeras alterações na cavidade bucal que poderiam passar despercebidas pelo cirurgião-dentista ou até mesmo de difícil percepção apenas pelo método visual. O objetivo do presente estudo foi demonstrar o uso do sistema de fluorescência óptica por imagem no diagnóstico de diferentes lesões da cavidade bucal, seja em tecido duro ou mole, de forma a familiarizar o cirurgião-dentista com o uso do equipamento. Para este estudo foi utilizado um equipamento constituído de um diodo emissor de luz (LED), com emissão na região do violeta e um conjunto de filtros ópticos (Evince - MMoptics, São Carlos, SP, Brasil). Para a aquisição das imagens foi acoplado ao equipamento uma câmera fotográfica (Nikon, D90, Bangkok, Tailândia) com o auxílio de um adaptador. O sistema de fluorescência bucal possibilitou observar alterações nos tecidos duros dentais como manchas, presença de placa e cálculo dental, lesões incipientes e infiltrações marginais, além de facilitar a diferenciação entre materiais restauradores como resina composta e cerâmica. Em tecidos moles foi possível detectar lesões potencialmente malignas e lesões tumorais. Portanto, pode--se concluir que o sistema de fluorescência óptica permite ao cirurgião-dentista diagnosticar e identificar estruturas e alterações na cavidade bucal de forma simples, não invasiva e em tempo real revelando lesões que não seriam facilmente detectados com a iluminação convencional.Fluorescence techniques can be used as an adjunct to clinical examination of the mouth, detecting tissue changes in oral mucosa or hard dental tissues, which might be unnoticed by the dentist or even difficult to detect under white light examination. The aim of this study was to demonstrate the use of wide-field fluorescence imaging in the diagnosis of various lesions of the oral cavity, either in hard or soft tissues, in order to familiarize the dentist with the use of the equipment. For this study we used an optical fluorescence system with emission in the violet region (Evince, MMOptics, São Carlos, SP, Brazil). For image acquisition, the fluorescence system was coupled to a digital camera (Nikon D90, Nikon, Bangkok, Tailândia). With the fluorescence system was possible to observe changes in hard dental tissues such as bright spots, dental plaque and calculus, incipient carious and marginal microleakage lesions. The system also facilitated the differentiation between restorative materials such as composite resin and ceramic. The fluorescence optical was also helpful in screening and detection of potentially malignant lesions and tumors could be observed. Therefore, we conclude that the fluorescence optical system allows the dentist to identify structures and alterations in the oral cavity in a simple, noninvasive, and in real-time procedure, revealing injuries that would not be easily detected with conventional illumination.FAPESPCNPqCAPESCEPID - CePOFInstituto Nacional de Ciência e Tecnologia de Óptica e Fotônica (INCT - INOF

    Tensile bond strength and SEM analysis of enamel etched with Er:YAG laser and phosphoric acid: a comparative study In vitro

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    Er:YAG laser has been studied as a potential tool for restorative dentistry due to its ability to selectively remove oral hard tissue with minimal or no thermal damage to the surrounding tissues. The purpose of this study was to evaluate in vitro the tensile bond strength (TBS) of an adhesive/composite resin system to human enamel surfaces treated with 37% phosphoric acid, Er:YAG laser (lambda=2.94 mum) with a total energy of 16 J (80 mJ/pulse, 2Hz, 200 pulses, 250 ms pulse width), and Er:YAG laser followed by phosphoric acid etching. Analysis of the treated surfaces was performed by scanning electron microscopy (SEM) to assess morphological differences among the groups. TBS means (in MPa) were as follows: Er:YAG laser + acid (11.7 MPa) > acid (8.2 MPa) > Er:YAG laser (6.1 MPa), with the group treated with laser+acid being significantly from the other groups (p=0.0006 and p= 0.00019, respectively). The groups treated with acid alone and laser alone were significantly different from each other (p=0.0003). The SEM analysis revealed morphological changes that corroborate the TBS results, suggesting that the differences in TBS means among the groups are related to the different etching patterns produced by each type of surface treatment. The findings of this study indicate that the association between Er:YAG laser and phosphoric acid can be used as a valuable resource to increase bond strength to laser-prepared enamel.A tecnologia a laser tem sido estudada como uma ferramenta potencial para uso em odontologia devido à sua habilidade em remover tecido ósseo com um mínimo ou nenhum dano aos tecidos vizinhos. O objetivo deste estudo é comparar in vitro a resistência à tração do sistema adesivo em esmalte tratado com ácido fosfórico a 37 %, laser Er:YAG (lambda=2,94 mim) com energia total de 16 J (80 mJ/pulso, 2 Hz, 200 pulsos e largura de pulso de 250 ms) e com a combinação laser Er:YAG seguido por ácido fosfórico. O teste de resistência à tração foi usado para comparar a resistência à tração em cada grupo. Foi também realizada microscopia eletrônica de varredura para permitir a análise das diferenças morfológicas entre os grupos. Foram obtidos os seguintes valores médios de resistência para os grupos tratados com: laser (6,1 MPa), ácido fosfórico (8,2 MPa) e laser mais ácido (11,7 Mpa). Amostras tratadas com laser e ácido apresentaram valores maiores de resistência do que amostras com laser ou ácido isoladamente. A análise da microscopia eletrônica revelou diferenças que corroboram os resultados, demonstrando que diferenças de resistência entre os grupos são devidas às diferenças entre os padrões superficiais resultantes. Nossos resultados sugerem que a combinação do laser Er:YAG com ácido fosfórico pode ser usada como um método para aumentar a resistência à tração do sistema esmalte resina

    Laser therapy in the treatment of dentine hypersensitivity

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    Cervical dentine hypersensitivity is the most frequent complaint among reported odontalgias. Thus, this study evaluated the effectiveness of two types of lasers (660 nm wavelength red, and 830 nm wavelength infrared) as dentine desensitizers, as well as both the immediate and late therapeutic effects in individuals 25 to 45 years of age. A total of 40 teeth with cervical exposure were treated in 4 sessions. They were divided into 2 groups according to treatment. A 660 nm wavelength red diode laser and an 830 nm wavelength infrared diode laser were used. Dentine sensitivity to cold nociceptive stimulus was evaluated by means of a pain numeric scale from zero to 10 before each treatment session, at 15 and 30 min after irradiation, and in a follow-up period of 15, 30 and 60 days after the end of treatment. Significant levels of dentinal desensitization were only found in patients ranging in age from 25 to 35 years. The 660 nm red diode laser was more effective than the 830 nm infrared laser and a higher level of desensitization was observed at the 15 and 30 minute post-irradiation examinations. The immediate and late therapeutic effects of the 660 nm red diode laser were more evident in 25-35-year-old patients compared with those of the 830 nm infrared diode laser, in terms of the different age groups.A hipersensibilidade dentinária cervical é a queixa mais frequente entre os relatos de odontalgia. Este estudo avaliou a eficácia de dois tipos de lasers, vermelho com 660nm e infravermelho com 830nm de comprimento de onda, como dessensibilizadores dentinários, como também os efeitos terapêuticos imediato e tardio em indivíduos de 25 a 45 anos de idade. Um total de 40 dentes com exposição cervical foram tratados em 4 sessões, divididos em 2 grupos - laser vermelho e infravermelho. A sensibilidade dentinária ao estímulo nociceptivo frio foi avaliada por meio de uma escala numérica de dor, de 0 a 10, antes de cada sessão de tratamento, aos 15 e 30 minutos após a irradiação e num período de seguimento de 15, 30 e 60 dias após o término do tratamento. Níveis significantes de dessensibilização dentinária foram apenas encontrados em pacientes com idade entre 25 a 35 anos. O laser díodo vermelho de 660nm foi mais eficaz comparado com laser infravermelho de 830nm e foi observado um nível mais alto de dessensibilização nas mensurações realizadas aos 15 e 30 minutos após irradiação. O efeito terapêutico imediato e tardio do laser díodo vermelho de 660nm é maior quando comparado com o infravermelho de 830nm em ambas faixas etárias.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Federal University of São Paulo EPMFederal University of Bahia School of Dentistry Laser CenterCamilo Castelo Branco University Laser CenterUNIFESP, EPMSciEL

    Microleakage of “bulk-fill” composite resin for class II restorations pretreated with CO2 laser in deciduous molars: an in vitro study

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    Introduction: Microleakage has been reported to cause dentin hypersensitivity because of the passage of bacteria and their products through the restoration-tooth interface and is one of the main reasons for replacement of restorations. CO2 laser can be used for treatment of dentin hypersensitivity. Thus, this study aimed to evaluate in vitro the microleakage in composite restorations following surface pretreatment with acid etching and CO2 laser.Methods: Twelve human caries-free primary molars were selected. Class II cavities were prepared on occlusal mesial and occlusal distal surfaces. Specimens were randomly divided into four groups (n = 6): Group 1 (G1) – 37% phosphoric acid gel etching + Beautiful-Bulk Restorative – Giomer (Shofu Inc); Group 2 (G2) – 37% phosphoric acid gel etching + SDR Bulk-Fill Flow (Dentsply); Group 3 (G3) – CO2 laser irradiation + Beautiful-Bulk Restorative – Giomer (Shofu Inc); Group 4 (G4) – CO2 laser irradiation + SDR Bulk-Fill Flow (Dentsply). Surfaces were restored with bonding agent (Natural Bond DE, DFL). Specimens were cut longitudinally and immersed in 0.5% methylene blue solution for 4 hours. Microleakage scores were assessed under a magnifying glass at x3,5 and qualitatively analyzed by scanning electron microscope (SEM). Data were analyzed using nonparametric Wilcoxon test (P < 0.05).Results: Scores prevailed between 0 and 2, however, no statistically significant difference was found among the groups (P = 0.05).Conclusion: It could be concluded that all composite resins bulk fill did not show significant difference among them regarding microleakage using either CO2 laser or 37% phosphoric acid etching.  

    Photobiomodulation for the Treatment of Primary Headache: Systematic Review of Randomized Clinical Trials.

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    peer reviewedThe purpose of this study was to evaluate the efficacy and safety of photobiomodulation as an adjuvant treatment for primary headache. A systematic review of randomized clinical trials was performed. For such, electronic searches were performed in the MEDLINE, Embase, Cochrane Library, LILACS, PEDro, PsycInfo, Clinicaltrials.gov., and WHO/ICTRP databases, with no restrictions imposed regarding language or year of publication. We included studies that assessed any photobiomodulation therapy as an adjuvant treatment for primary headache compared to sham treatment, no treatment, or another intervention. The methodological assessment was conducted using the Cochrane Risk of Bias tool. The certainty of the evidence was classified using the GRADE approach. Four randomized clinical trials were included. Most of the included studies had an overall high risk of bias. Compared to sham treatment, photobiomodulation had a clinically important effect on pain in individuals with primary headache. Despite the benefits reported for other outcomes, the estimates were imprecise, and the certainty of the evidence was graded as low. These findings are considered insufficient to support the use of photobiomodulation in the treatment of primary headache. Randomized clinical trials, with higher methodological quality, are needed to enhance the reliability of the estimated effects

    Immediate Evaluation of the Effect of Infrared LED Photobiomodulation on Childhood Sleep Bruxism: A Randomized Clinical Trial.

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    peer reviewedThe gold standard for the management of sleep bruxism (SB) is the use of a rigid occlusal splint; however, there are limitations for its use in children and alternatives to the management of SB are needed. Photobiomodulation therapy has been used with positive results in temporomandibular disorders. This study aimed to evaluate the effects of photobiomodulation therapy with infrared LED in children with SB. Thirty children were divided into three groups: Group 1: control/absence of bruxism (n = 10); Group 2: SB treated with infrared LED (n = 10); Group 3: SB treated with occlusal splint (n = 10). Electromyographic evaluation of masseter, anterior temporalis, and upper trapezius, and salivary dopamine levels were assessed before and after treatments. Data were statistically analyzed using two-way mixed model ANOVA. An increase in the temporalis and right masseter EMG activity at rest was observed in Group 3, with large effect size (p < 0.05). Left masseter and temporalis EMG activity did not differ over time in the LED group, similar to the control group. Moreover, the EMG activity of masticatory muscles during chewing and upper trapezius muscle did not differ over time in all groups. The results also pointed to a difference in the levels of dopamine between children with and without SB, with Group 3 showing higher levels in the pre-treatment time compared to controls (p < 0.025). In conclusion, an increase in the masticatory muscles activity at rest was observed in children undergoing splint therapy. Moreover, a difference in the levels of salivary dopamine was found between children with and without SB.3. Good health and well-bein

    In vitro influence of photodynamic antimicrobial chemotherapy on staphylococcus aureus by using phenothiazines derivatives associated with laser/LED Light

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    ABSTRACT The aim of this study was to evaluate the effect of photodynamic antimicrobial chemotherapy (PACT) using phenothiazinium dyes -PTZ irradiated with red laser (ʎ660nm) or red-orange LED (ʎ632±2nm) on Staphylococcus aureus in vitro. triplicate tests were performed in 10 groups: control, Laser (L1 + P -and L2 + P -) bacterial suspensions were irradiated only with laser energy 2.4 and 4.8 J/cm 2 respectively, (Led1 + P -and Led2 + P -) irradiated only with LED energy 2.4 and 4.8 J/cm 2 respectively, (L1 + P + and L2 + P + ) irradiated with laser in the presence of 1μg/ml of photosensitizer, (Led1 + P + and Led2 + P + ) irradiated with LED in the presence of 1μg/ml of photosensitizer and finally (L -P + ) only in the presence of PTZ dye. Bactericidal effect of the PACT was assessed by counting colony-forming units. The results showed no significant difference on regards different energy densities on group PACT for both lights. PACT groups (L2 + P + and Led2 + P + ) compared to the Control showed significant reduction of CFUs. LED/Laser groups (L2 + P -and Led2 + P -) compared to control and PTZ groups showed also significant differences as groups LED/Laser (4.8J/cm 2 ) increased the average of CFUs. Although the results of this study have shown a reduction in average number of colonyforming units by the appropriate Laser or LED-dye treatment combination, it this topic requires further investigation

    Effect of Photobiomodulation Combined with Physiotherapy on Functional Performance in Children with Myelomeningo-Cele-Randomized, Blind, Clinical Trial.

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    peer reviewed[en] BACKGROUND: This study aimed to evaluate the electrical activity of the rectus femoris, tibialis anterior, and lateral gastrocnemius muscles during the sit-to-stand task and functional mobility after a neurofunctional physiotherapy protocol associated with PBM. METHODS: Twenty-five children were randomly allocated to either Active PBM + physiotherapy (n = 13) or PBM sham + physiotherapy (n = 12). PBM was carried out with a LED device (850 nm, 25 J, 50 s per point and 200 mW) at four points over the area with absence of a spiny process. Both groups completed a twelve-week supervised program with two weekly 45-60 min sessions. Pre-training and post-training assessments involved the Pediatric Evaluation of Disability Inventory (PEDI). Muscle activity was assessed using portable electromyography (BTS Engineering) and the electrodes were positioned on the lateral gastrocnemius, anterior tibialis, and rectus femoris muscles. The RMS data were recorded and analyzed. RESULTS: After 24 sessions of the treatment protocol, improvements were found in the PEDI score. The participants presented greater independence in performing the tasks, requiring less assistance from their caregivers. More significant electrical activity was found in the three muscles evaluated between the rest period and execution of the sit-to-stand tasks, both in the more compromised or less compromised lower limbs. CONCLUSION: Neurofunctional physiotherapy with or without PBM improved functional mobility and electrical muscle activity in children with myelomeningocele

    Implementation and performances of the IPbus protocol for the JUNO Large-PMT readout electronics

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    The Jiangmen Underground Neutrino Observatory (JUNO) is a large neutrino detector currently under construction in China. Thanks to the tight requirements on its optical and radio-purity properties, it will be able to perform leading measurements detecting terrestrial and astrophysical neutrinos in a wide energy range from tens of keV to hundreds of MeV. A key requirement for the success of the experiment is an unprecedented 3% energy resolution, guaranteed by its large active mass (20 kton) and the use of more than 20,000 20-inch photo-multiplier tubes (PMTs) acquired by high-speed, high-resolution sampling electronics located very close to the PMTs. As the Front-End and Read-Out electronics is expected to continuously run underwater for 30 years, a reliable readout acquisition system capable of handling the timestamped data stream coming from the Large-PMTs and permitting to simultaneously monitor and operate remotely the inaccessible electronics had to be developed. In this contribution, the firmware and hardware implementation of the IPbus based readout protocol will be presented, together with the performances measured on final modules during the mass production of the electronics

    Mass testing of the JUNO experiment 20-inch PMTs readout electronics

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    The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose, large size, liquid scintillator experiment under construction in China. JUNO will perform leading measurements detecting neutrinos from different sources (reactor, terrestrial and astrophysical neutrinos) covering a wide energy range (from 200 keV to several GeV). This paper focuses on the design and development of a test protocol for the 20-inch PMT underwater readout electronics, performed in parallel to the mass production line. In a time period of about ten months, a total number of 6950 electronic boards were tested with an acceptance yield of 99.1%
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